1. Field of the Invention
The present invention relates to an exterior antenna structure of a mobile terminal. More particularly, the present invention relates to an exterior antenna structure of a mobile terminal that may extend the length of an antenna pattern when it is inserted into a case.
2. Description of the Related Art
In recent years, in a mobile terminal such as a portable phone, demand for a function of receiving mobile broadcasting, such as Digital Multimedia Broadcasting (DMB), Integrated Services Digital Broadcasting-Terrestrial (ISDB-T), Digital Video Broadcasting-Handheld (DVB-H), Media Forward Link Only (MediaFLO), as well as a voice communication function, is increasing. An exterior antenna such as a whip antenna has been widely used as an antenna for receiving mobile broadcasting. In this case, the exterior antenna can be inserted or extended into or from a case, respectively.
FIG. 1 is a plane view illustrating an exterior antenna structure of a mobile terminal according to the related art.
Referring to FIG. 1, the exterior antenna structure of a mobile terminal includes an exterior antenna 10 with a sleeve 14 and a stopper 16. A head 12 is formed at an upper end of the sleeve 14. A tube 15 is formed at an inner side of the case 11, and guides insertion or extension of the sleeve 14 and the stopper 16 into or from the case 11. A cover 17 is inserted into a lower end of the tube 15 to prevent a stopper 16 from being extended from an inside of the tube 15. A power supply unit 13 is provided at an upper end of the tube 15 to contact with the sleeve 14 or the stopper 16. The stopper 16 is connected to a lower portion of the sleeve 14 by a hinge engagement portion 19.
In the exterior antenna structure of a mobile terminal having the construction mentioned above, since the exterior antenna 10 is inserted into an inside of the case 11 at the time of a scheduled recording of mobile broadcasting, a passive gain is 30 decibels (dB) lower in comparison with a case where the exterior antenna 10 is extended. When a side key and the case 11 of the exterior antenna 10 are made of metal for improving the reliability, a passive gain is 10 dB lower in comparison with a case where they are made of plastic materials.
Therefore, a need exists for an exterior antenna structure of a mobile terminal that may minimize a reduction in a passive gain when an exterior antenna is inserted into a case.